Jack



. D. E. HENNESSY.

JACK.

APPLICATION men JULY 14. 1915.

Patented June 21, 1921.

2 SHTS-SHEET 1 witnesses:

D. E. HENNESSY.

JACK.

APPLICATION FLLED JULY I4, 1915.

nuewfo'e ZSHEETS-SHEET 2.

Patented June 21, 1921.

NM QR v wg and said means.

UNITED STATES DANIEL E. HENNESSY, 0.1 HOLYOKE, MASSACHUSETTS, ASSIGNOR TO HERBERT WI COWAN, J. LEWIS WYCKOFF, AND EDWARD N. WHITE, TRUSTEES, DOING BUSI NESS AS COW ALN TRUCK COMPANY.

PATENT OFFICE.

JACK.

Specification of Letters Patent. Patented J 11119 21 1921 Application filed July 14, 1915. Serial No. 39,729.

To all whom it may concern:

Be it known that I, DANIEL E. HENNnssY, a citizen of the United States, residing at Holyoke, county of Hampden, and State of Massachusetts, have invented certain new anduseful Improvements in Jacks, of which the following is a clear, full, and exact description. I

This invention relates to jacks, and particularly to the means for effecting the movementof the jack-post of a jack.

A general object of the invention isto provide a simple and powerful mechanically operated jack. V

More particularly the invention aims to provide improved means for engaging the jack-post of a jack to effect its movement or to retain it in the position'to which it. has

been moved, which means will be positive and certain in operation and will effectively engage the jack-post at any point within the range of relative movement of said post The invention is herein shown as embodied in a jack which is particularly. adapted for use in raising the platform of a truck for transporting heavy articles, but it will be understood that the showing is merely illustrative of one application of the invention and is not intended to affect the scope of the protection sought.

An important feature of the invention is the arrangement of two nuts upon a steeply threaded j ack-post in such manner that-the nuts are alternately held against turning on said post, whereby by relative movements of approach and separation of saidnuts a jacking movement of said post is effected.

Other features and important objects of the invention will appear from the following description and claims when considered in connection with the accompanying drawings, in which-- Figure 1 is a plan view of the improved jack, which constitutes the subject-matter of this invention;

Fig. 2 is a side elevation with parts in section, a portion of a truck frame and a pla form being shown in this view;

Fig. 3 is a longitudinal section;

Fig. 4 is arear elevation of the jack-releasing means; V

Fig. 5 is a bottom plan view of the mechanism shown in Fig. 4;

Fig. 6 is a rear elevation of the jack locking nut; and

F 1g. 7 is a rear elevation of the jack operating nut.

As hereinabove suggested, the jack, which is the subject-matter of this invention, is particularlyadapted for use with so-called elevating trucks, and for the purposes of the description the jack is shown in connection with the cooperating parts of an elevating truck. This truck may be of the general type disclosed in my copending application, Serial No. 194,591, filed Oct. 3, 1917, and comprises a frame 2 having an upwardly and forwardly arched portion 4, in which thesteering-wheel or caster (not shown) has its bearings and a platform 6 arranged for a compound movement of elevation upon the frame, comprisinga shiftpound movement may be obtained in any suitable way, as for example by inclined members such as shown in my copending application, Serial N 0. 194,591, hereinabove referred to.

The jack by which the shifting and lifting movement of the platform 6 is effected is pivotally mounted upon the truck frame 2 so that it may swing about its pivots 8 as the platform is raised, and this jack comprises a jack post 10 having rigidly attached to its outer end a head 12 pivoted between ears 14 on a bracket 16 attached to the underside of the platformG. The jackpost 10 is provided with steep threads or grooves 18, theillustrated jack post having three of these threads. Mounted upon the jack post are two nuts 20 and 22, the nut 20 being threaded to cooperate with all three of the threads18 upon the jack post, and the nut 22 having two threads which cooperate with two of the three threads 18 of the jack post. The purpose of this difference in thethreading of the two nuts will appear hereinafter. t

It will be noted that the threading of the jack post 10 is so steep that a movement of the jack post through the nuts 20 and 22. or

longitudinal movement of the heir post ro- Q 7.1

vision is made for relative movements of,

approach and separation of the nuts and for alternately holding the nuts against turning. In the illustrated construction the nut 20 is mounted in a bearing member 24, which is carried upon the pivots 8 and is thus free to turn about said pivots during the operation of the jack but is held against movement lengthwise of the frame 2. The nut 20 is provided with a conicalclutching surface 26, which cooperates with the correspondingly shaped inner face 28 in the rear end of the bearing member 24. A cylindrical neck portion 30 of the nut 20is received in a corresponding cylindrical bore 31 in the bearing member 24, said neck portion being threaded at its forward end to receive a nut or collar 32 by which said nut 20 is confined in the bearing member, the collar 32 being so'located upon the nut 20 that provision is made for movement of the nut 20 in the bore 31 whereby the clutchingsurface 26 upon the nut 20 may be moved into and out of engagement with the coeperating surface 28 upon the bearing member 24. This movement of the nut 20 through the bore of the bearing 24 is sufficiently free so that it will be effected by-the' movement of the jack post. The nut 22, like the nut 20, has a'conical clutching surface 34 which cooperates with the correspondingly shaped inner surface 36 in a bearing member 38 for said nut 22.

The nut 22, like the nut 20, also has a cylindrical neck portion 40 received in a cylindrical bore 41 in the bearing member 38 and threaded at its forward endto receive a collar 42 which confines said nut in its bearing. The bearing member 38 is provided with trunnions 44 which receive links 46 pivotally connected at 48 to a lever 50, of the second class, fulcrumed at 52 upon a bracket 54 at the forward end of the truck frame 2. Uscillation of said lever 50 about its fulcrum 52 effects, through the links 46, a reciprocation of the bearing member 38 upon the jack post 10. The nut 22, like the nut 20, is confined in its bearing member with provision for limited movement lengthwise of said member, whereby the surface 34 upon the said nut is moved into and out of clutching relation to the surface 36 on said member.

From the foregoing description it will be seen that when the bearing member '38 is moved toward the'rear of the truck, that is, toward the right in each of the figures in 3 which it is shown, it will be brought into clutching relation to the nut 22 and will not only carry the nut with it but will also prevent it from turning upon the jack post 10, thereby causing the jack post also to be moved with said bearing member". Such movement of the jack post moves the nut 20 out of clutching relation to its bearing member 24, whereby the nut 20 is free to'turn upon the jack post as the jack post is moved through it. When the bearing member 38 is again moved toward the front of the truck, that is, toward the left in each of the figures in which it is shown, it moves out of clutching relation to the nut .22, thus permitting this nut to turn freely upon the jack post. At the same time the tendency of the jack post to move back to its original position causes the nut 20 to be moved into clutching relation to the bearing member 24, whereby this nut is prevented from turning and the jack post is thus held substantially in the positionto which it has been moved by the movement'of thebearing member 38 toward the rear of the truck. The jack post being held by the nut 20, the nut 22 is moved to a new position upon the jack post, and when the bearing member'38 is again moved toward the rear of the truck, the jack post is advanced still farther in its platform-lifting direction.

A lever 56, fulcrumed at 58 upon the arched portion 4 of the truck frame, has a pin (SO-received'in a slot 62 in the upper end of the lever 50 and is provided with a stop 64 arranged to engage a stop 66 upon the truck frame to limit the rearward movement of said lever. The lever 56 may be connected in any suitable manner to the handle by which the truck is drawn and steered, whereby it may be operated by a forward and backward movement of said handle to effect the oscillation of the lever 50, a suit able connectionto the draft handle'of the truck being shown in my copending applica tion Serial No. 194,591.

It will be apparent that in order to release the jack to permit the load platform to be hold the nut 20 in released position will first V be described.

The bearing member 24 for the nut 20 has a cylindrical extension 68 on the forward side of its pivotal axis, which is threaded to receivea cap 70, having a central bore through which the jack post 10 moves, and having a stud 72 projecting from its front face below said jack post. The stud 72 serves as a crank pin by which the cap may be screwed back and forth upon the cylindrical part68 of the bearing member. Between the inner face of the cap 70 and the forward end of the nut 20 is a washer 74. When the parts are in the position shown in Fig. '3,it will be seen that the washer 7 4 fills the space between the end of the nut 20 and the inner face of the cap 70, the nut 20 being in its released condition, thus preventing'the nut from moving into nut 20 may move freely into and out of clutching relation to the: bearing, member 24.

The means for moving the cap 70 into the position shown in Fig. 3 comprises a bellcrank lever 76 having on one arm an upwardly extending forked portion 78 which embraces the stud 72, the other armr80 of the bell-crank lever being bent upwardly out of the plane .of the first mentioned arm, and having a universal joint connection 82 with a link or rod 84 connected at its other end to the lower arm of a treadle lever 86, fulcrumed at 88 upon the truck frame. A spring 90 confinedbetween thecollar 92on the rod 84, and an upstanding ortion 94 of the truck frame, tends to hol the treadle lever 86 in its elevated position and to hold the bell-crank 7 6 in such position thatthe cap 70 is maintainedin the j ack-operatin position. In order that the nut 22 may also be held in such relation to its bearing member 38 that it will turn freely on the jack post as said post moves toward the platformdowering position, an abutment 98 is provided against which the forward end of this nut strikes when the carrier 38 is moved to itsextreme forward position, thus effecting a relative movement of the carrier and nut into unclutching relation.

In order thatthe operator ma retard the lowering of the platform, bra ing means have been embodied in the jack-releasing means, the illustrated braking means comprising a conical friction surface 96 upon the collar 32, which cooperates with a correspondingly shaped friction surface upon the inside of the bearing member 24. These two surfaces are preferably so shaped that they do not constitute a locking couple It will be seen that as the operator presses his foot upon the treadle portion 87 of the treadle lever 86, he effects the turning of the cap 70 to release the locking couple 20, 24, and further depression moves the friction surface 96 into contact with the friction surface on the member 24, thereby retarding the turning ofthe nut 20. The degree of the retarding action depends obviously upon the pressure exerted upon the treadle 87 i V In order to limit the lifting movement of the jack, a plug or stop 97 is located in that one of the threads 18 of the jack-post 10 which has no corresponding thread in the nut22. The stop 97 will thus pass through the nut 22 and into engagement with the front end of the threadin the nut 20 which travelsin said groove or thread in which the stop is located. It will thus be seen that the ja-ck can be extended by the operation of the nut 22-substantially to the endof the jack-post 10, and that the stop 97 will prevent over-extension or movement of the jack-post 10 out of operative relation to the nuts.

What- I claim as new is l; A jack" comprising, in combination, a

jack-post having a thread thereon so inclined to its axis'that' a nut screwed upon saidthreadmay'be turned by relative movement of said post and said nut along said aXis,,anut on said post, means for recipro-, ca'tingsaid nut, and means acting automatically as said nut is moved in one direction it carries said post with it. 7

2. A jack comprising, in combination, a jack-post having a threadthereon so inclined to itsaxis that a nut screwed upon said threadmay'be turned by relative movement of said post and said nut along said axis, two nuts on. saidupost relatively movable toward and awayfrom each other, and means whereby each is prevented from rotationi while a relative movement of the post andthe other nut takes place.

3;,A' jack comprising, in combination, a steeply threaded jack-post, twonuts upon said jack-post, means for effecting relative movements of approach and separation of said nuts', and.means operating in timed relation to said last mentioned means for alternately. holding said nuts against turning on said post. 1 4. A 'aek' comprising, in combination, a jack-post having a thread thereon so inclined to itsaxis that a nut screwed upon said thread may be turned by relativemovement of said post and said nut along said axis, a nut on said post, a carrier for said nut movable along said post and in which said nut may turn, means on said carrier to prevent turning of said nut as said carrier moves in one direction, whereby said carrier moves the jack-post with it, and means for retaining said jack-post in the position to which it is moved by said carrier.

5. A jack comprising, in combination, a jack-post having a thread thereon so inclined to its axis that a nut screwed upon saidthread maybe turnedby relative movement ofsaid post and said nut alongsaid axis, two nuts on said post, means. for vmoving one of said nuts toward and awayfrom the other, means for preventing the rotation of said movable nut as it is moved toward the other nut, whereby it carries the jackpost with it, and means for preventingthe rotation of saidsecond nut as said movable nut moves away therefrom, whereby the return of said jack-post is'prevented.

to prevent its turning on said post whereby ire jaek post having a thread thereon so in- V which said nut is confined with provision for turning movement about its axis and for limited movement along its axis, said nut and said bearing having cooperating clutch ing portions arranged to be moved into and out of operative engagement by the relative movements of said nut and said bearing along said axis. 7

7. A jack comprising, in combination, a jack-post having a thread thereon so inclined to it axis that a nut screwed upon said thread may be turned by relative movement of said post and said nut along said axis, two nuts 7 on said post relatively movable toward and away from each other, and a bearing for each nut in which said nut is confined with provision for turning movement about its axis and for limited movement alongits axis, said nut and said bearing having cooperating clutching portions arranged to be moved into and out of operavtive engagement by the relative movements of said nut and said bearing along said axis.

8. A- jack. comprising, in combination, a jack-post having a thread thereon so inclined vto its axis that a nut screwed upon said thread may be turned by relative movement of said post .and said nut along said axis, two nuts on said post relatively movable toward and away from each other, and a bearing for each nut in which said nut is confined with provision for turning movement about its axis and for limited movement along its axis, said nut and said bearing having coeperating clutching portions arranged to be moved into and out of operative engagement by the relative movements of said nut and said bearing along said axis, both of said bearing and nut couples moving to open position in the same direction along said axis.

9."A jack comprising, in combination, a steeply threaded jack post, two nuts upon said jack post, means for effecting relative movements of approach and separation of 7 said nuts, means operating in timed relation to saidlast mentioned means for alternately holding saidnuts against turning on said post, and means for preventing the operation of said holding meanswhen release of said jack is desired. V

10. A. jack comprising, incombination, a steeply threaded jack post, two nuts upon said jack post, means for effecting relative movements of approach and separation of said nuts, means operating in timed relation to said last mentioned means for alternately holding said nuts against turning on said post, hand-operated means for effecting the relative movements of said nuts,

means for holding said clutching portions.

out of clutching relation to release said jack. 7

12. A jack comprising, in COIIlblI12tl31011,'2L

steeply threaded jack post, 'tWo nutsupon said jack post, a stationary bearing member in which one of said nuts is'rotatably mounted, a reciprocating bearing member in which the other nut is rotatably mounted andbvwhich it may be moved toward and away from said first mentioned nut, and cooperating means upon each bearing member and the associated nut arranged tooperate in timed relation to the reciprocating movements of said reciprocating member for alternately locking said nuts against rotation in their respective bearing members.

' 13. A jack comprising, in combination, a steeply threaded jack post, two nuts upon said jack post, a stationarv bearing member in -which one of said nuts is rotatably mounted, a reciprocating bearing member in which the other nut is rotatably mounted. and by which it may be moved toward and away from said firstmentioned nut, cooperating Ineansupon each bearing member and the associated nut, arranged to operate in timed relation to the reciprocating move ments of said reciprocating member for al ternately locking said nuts to their respective bearingfmembers, and means upon one of said bearing members whereby the operation of saidflocking means may be prevented. A 1

M. A jack, comprising, in combination, a steeply threaded jack post, two nuts upon said jack post, means for effecting relative movements of approach and separation of said nuts, means operating in timed relation to said last mentioned means for alternately holding said nuts against turning on said post, and a stop on said jackpost cooperating with one of said nuts to limit the movement of'said jack post.

V 15. A jack, comprising, in combination, a jack post having a plurality of steep threads, two nuts upon saidjack post, one of said nuts having a less number of threads than the other, and a stop located in that thread of the jack post which has no corresponding thread in the last mentioned nut.

16. A jack comprising, in combination, a

steeply threaded jack 0st, two nuts upon said jack post, means for effecting relative movements of approach and separation of said nuts, means operating in timed relation to said last mentioned means for alternately holding said nuts against turning on said post, and means for limiting the movement of the jack post constructed and arranged to travel freely through one of said nuts but to be stopped by the other.

17 A jack comprising, in combination, a steeply threaded jack post, two nuts upon said jack post, a stationary bearing member in which one of said nuts is rotatably mounted, a reciprocating bearing member in which the other nut is rotatably mounted and by which it may be moved toward and away from said first mentioned nut, cooperating means upon each bearing member and the associated'nut arranged to operate in timed relation to the reciprocating movements of said reciprocating member for alternately locking said nuts against rotation in their respective bearing members, and a stop carried by said jack post and constructed and arranged to pass freely through the reciprocating nut into operative engagement with the nut carried by said stationary bearing member.

18. A jack comprising, in combination, a jack-post, means for moving said jack-post, means for retaining said post in the position to which it is moved by said moving means, and means carried by said jack-post constructed and arranged to pass' one of said aforementioned means in the operation of extending the jack and to engage the other to prevent over-extension of the jack. 19. A jack comprising, in combination, a jack-post, jack-post lifting means and jackpost retaining means both arranged to embracesaid jack-post, and a stop carried by said jack-post adapted to pass one of said aforementioned means and to engage the other for preventing over-extension of the 'ack. J 20. In apparatus of the class described, the combination with members arranged for combined longitudinal and transverse rela-- tive movement in substantial parallelism, and rectilinearly separable jack members respectively pivotally connected to said aforementioned members, whereby said ack may swing bodily during the relative movement of said aforementioned members, of moving and retaining means associated with the separable jack members and arranged for limited rectilinear movement therewith, and means mounted upon one of the first mentioned members and having operative connection with said retaining means in any swinging position of said jack for releasing said retaining means.

Signed at Holyoke, Mass, this 12th day of July, 1915.

DANIEL E. HENNESSY.

Witnesses:

HARRY W. CARTRIDGE, G. F. JENKs. 

